SmogRank / History / Country race
Countries, worst air first, day by day
Each country's typical measured city over the 30 days to every day since January 2023, worst first. Press Play to watch the order change, or drag the slider to any day.
The worst countries for PM2.5 over the 7 days to 15 Jan 2026: Pakistan 188.2 µg/m³, Kazakhstan 92.1 µg/m³ and Montenegro 72.5 µg/m³.
- 1Pakistan12 cities188.2
- 2Kazakhstan4 cities92.1
- 3Montenegro4 cities72.5
- 4North Macedonia10 cities47.0
- 5Ghana4 cities40.4
- 6Thailand78 cities36.8
- 7Hungary13 cities34.5
- 8Romania24 cities32.7
- 9Poland57 cities30.4
- 10Hong Kong13 cities28.3
- 11Slovenia12 cities26.7
- 12Austria42 cities22.1
- 13Bulgaria4 cities20.4
- 14Taiwan44 cities20.1
- 15Laos3 cities19.7
- 16Philippines3 cities19.5
- 17Latvia4 cities18.8
- 18South Korea139 cities17.5
- 19Chile46 cities17.3
- 20Peru6 cities17.0
+ 21 more countries, the next at 16.9 µg/m³
- 37United States871 cities, was 2655.5
Not counted on this day, too few cities measured: India since 13 Jan 2026, Senegal since 10 Jan 2026, Bosnia and Herzegovina since 9 Jan 2026 and 8 more countries.
Countries counted each day
A country's number is its typical measured city: the median of its cities' means over the 30 days (a city needs 21 of them measured; 5 of 7 on the 7-day race), shown only with 3 such cities. A country whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air; "was" beside a city count marks a month after many cities joined or left. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.